The invention is directed to a gearing for a door lock, having a lock follower or the like-(hereinafter simply called lock nut) and an actuating member therefor, particularly a panic or smoke-protection door lock. The gearing comprises a first gearing part being rotatable around a first axis and being connectable with said actuating member and a second gearing part which is rotatable around a second axis and is to be connected with a handle.
Doors are sometimes provided with handles whose rotation or swivel axes, in contrast to the axes of the lock nuts or the like of most latch and/or bolt locks, are not substantially perpendicular to the door leaf when the handles are mounted. Such doors are chiefly so-called panic doors which are provided, for instance, in public buildings or public entertainment locations such as cinemas or the like so as to provide, in cases of emergency, an escape route with an outwardly opening door which can be easily and reliably opened also during the outbreak of panic. For this purpose, the handles of these panic doors have handle bars which extend substantially along the entire width of the door and are arranged on the inside of the door and can be swiveled by hand or body pressure in the direction of a door leaf around a substantially horizontal axis in the mounted state and accordingly pull back the bolt as well as the latch of the respective door lock. The outside of panic doors is either completely smooth or provided with conventional handles in the form of latch handles, knobs or the like and possibly with keys for the locking bolt. Apart from emergency situations, such panic doors can also be advantageous for other purposes and are used, for instance, in hospitals or wherever there is the desire to open a door e.g. by the pressure of the arm or body. In such cases, an additional bolt can usually be dispensed with.
In addition, there are so-called smoke-protection doors which were previously constructed as swinging doors and provided with handle bars which are rigidly attached and arranged in the mounted state so as to be substantially vertical. In the future such smoke-protection doors will have to be constructed with latch locks and therefore also with swivelable handles. It may therefore be desirable to provide smoke-protection doors with handles which are arranged as swinging door handles which are swivelable substantially around a vertical axis when mounted.
Since the described handles are swiveled around axes which must be substantially perpendicular to the rotational axis of the lock nut, a gearing must be associated with the handles and locks which converts the rotational movement around the swivel axis of the handle into a rotational movement around the rotational axis of the lock nut perpendicular thereto. Numerous demands are made on such a gearing. First, the latch and the bolt must be drawn back completely by a swiveling movement of the handle e.g. by 30.degree. or 45.degree.. Further, it must be possible to unlock by exerting a slight predetermined pressure on the handle. Finally, it is desirable to provide such a gearing in doors with a continuous door leaf, e.g. fire doors, as well as in frame doors or the like in which the door leaf is produced predominantly from glass or the like and is enclosed only by a narrow frame, often with a width of only 42 mm, at which the handle must be mounted. Therefore, the gearing must be sufficiently stable and as frictionless as possible on the one hand, but must have a sufficiently small width on the other hand.
A known gearing of the generic type indicated in the introduction (EP 0 113 655 B2, DE 85 26 748 U1) in particular does not satisfy these last requirements. This is because the gearing is arranged adjacent to a sleeve for receiving a conventional actuating member for the lock nut, e.g. a square spindle, and therefore coaxially relative to it, has means in the form of driver pins and guides which act on the latter and are arranged radially outside of the sleeve contour. A small width of the overall construction is therefore still synonymous with poor stability. On the other hand, if the object is high stability-and accessibility so that all of the above-mentioned demands are satisfied, this necessarily requires a width of the overall arrangement which is so large as to render it unsuitable at least for frame doors with conventional frame widths and spindle dimensions (distance of the lock nut axis from the end face of the door or frame when the door is closed). In addition to this, there is also a risk when using the known gearing that the height of the overall arrangement perpendicular to the door leaf is so great that the door can no longer be opened outward when using conventional spindle dimensions because the gearing arrangement would strike against the frame or its lining.